NEW YORK (CNN) -- Liz Cheney, whose upstart bid to unseat Wyoming Sen. Mike Enzi sparked a round of warfare in the Republican Party and even within her own family, is dropping out of the Senate primary, she said in a prepared statement Monday morning.
"Serious health issues have recently arisen in our family, and under the circumstances, I have decided to discontinue my campaign," she said.
Cheney, the eldest daughter of former Vice President Dick Cheney, began telling associates of her decision over the weekend, CNN reported late Sunday night.
"Though this campaign stops today, my commitment to keep fighting with you and your families for the fundamental values that have made this nation and Wyoming great will never stop," she added.
Cheney's surprising decision to jump into the race, an announcement made in a YouTube video last summer, roiled Republican politics in the Wyoming, a state that Dick Cheney represented in Congress for five terms before moving up the Republican food chain in Washington.
Enzi was a low-key presence in Washington who was elected in 1996 and, with few blemishes, amassed a conservative voting record in the Senate. He expressed public annoyance at Cheney's decision to mount a primary challenge. A number of his Senate colleagues quickly rallied to his side and pledged support for his re-election bid.
There was little public polling of the race, but two partisan polls released last year showed Enzi with a wide lead, an assessment mostly shared by GOP insiders watching the race.
Cheney's campaign got off to a rocky start.
Her critics labeled her a carpetbagger, noting that she moved to Wyoming only in 2012 after relocating from Virginia. The issue flared in August after the Wyoming media reported that Cheney improperly received a fishing license despite not living in the state for at least a year, as the law requires.
Grabbing even more attention was her very public dispute with her sister, Mary, over the issue of same-sex marriage. Mary Cheney, who is a lesbian, took to Facebook in November to object to Liz Cheney's opposition to same-sex marriage, claiming that her sister has previously supported her relationship while saying something very different on the campaign trail.
The dispute prompted their parents to weigh in, saying they were "pained" to see the sisters battle over a private matter in full view of the news media.
Beyond the campaign missteps, Cheney's election effort, vigorously supported by her father and his allies, often felt out of tune with the small-government conservative sentiment that has fueled other Republican primary challengers.
Cheney, like her father, is an unapologetic neoconservative who favors muscular use of American military power overseas, a policy that does not sit well with many grassroots conservatives, particularly in the libertarian-leaning West.